Roger,
Your answer will go back to ARC's counsel no later than 30 days after the service of the Civil Summons. At this time you and the heirs of your family are at risk of losing 0.91836735 net mineral races if you decide not lease with ARC. The minerals in total are divided to over 200 heirs and can't be partitioned. Here's were ARC can file suit against any heir not willing to lease their minerals. Your asking why do I have to lease to ARC? The simple answer is the total net minerals can not be developed if heirs don't agree to lease with some energy company. In this case ARC is the developing energy company. Many legal items go with Oil and Gas Exploration to include: Land Leasing (Surface) and Mineral Leasing (Sub-Surface). My advice to you and the your heirs is to review the leasing document decide what leasing bonus and percent is fair - 12% to 15% is fair market for mineral leasing. Remember this is a non-producing field and will take years to develop. The first 5 year lease will be under a non-developed oil/gas field. Once developed and producing your family will be paid royalties under the agreed lease. If you do not sign the lease the courts will most likely grant an allotment of all unleased minerals in favor of ARC and allot or sell the minerals in question.